
body {
    background-image: url("http://p8.qhimg.com/bdm/2560_1600_100/t01fc7e26c37fe94287.jpg");
}
.keys {
    display: flex;
    min-height: 100vh;
    align-items: center;
    justify-content: center;
}

.key {
    border: 4px solid black;
    border-radius: 5px;
    margin: 1em;
    font-size: 1.5rem;
    padding: 1rem .5rem;
    transition: all .07s;
    width: 100px;
    text-align: center;
    color: white;
    background: rgba(0, 0, 0, 0.4);
    text-shadow: 0 0 5px black;
}

.playing {
    transform: scale(1.1);
    border-color: #ffc600;
    box-shadow: 0 0 10px #ffc600;
}

kbd {
    display: block;
    font-size: 40px;
}
